-Simple UEFI boot loader which executes configured EFI images, where the
-default entry is selected by a configured pattern (glob) or an on-screen
-menu.
+gummiboot Simple UEFI boot manager
-Operates on the EFI System Partition (ESP) only. Configuration file fragments,
-kernels, initrds, other EFI images need to reside on the ESP. Linux kernels
-need to be built with CONFIG_EFI_STUB to be able to be directly executed as
-an EFI image.
+gummiboot executes EFI images. The default entry is selected by a configured
+pattern (glob) or an on-screen menu.
-Reads simple and entirely generic boot loader configurion files; one
-file per boot loader entry to select from.
+gummiboot operates on the EFI System Partition (ESP) only. Configuration
+file fragments, kernels, initrds, other EFI images need to reside on the
+ESP. Linux kernels must be built with CONFIG_EFI_STUB to be able to be
+directly executed as an EFI image.
-Pressing the space (or most other) keys during bootup will show
-an on-screen menu with all configured loader entries to select from.
-Pressing enter on the selected entry loads and starts the EFI image.
+gummiboot reads simple and entirely generic configurion files; one file
+per boot entry to select from.
+
+Pressing Space (or most other) keys during bootup will show an on-screen
+menu with all configured entries to select from. Pressing enter on the
+selected entry loads and starts the EFI image.
If no timeout is configured and no key pressed during bootup, the default
entry is booted right away.
-The config files should be named like:
- (ESP)/loader/entries/<vendor>-<release>.conf
-
- $ cat /boot/loader/entries/fedora-3.5.4-1.fc18.x86_64.conf
- title Fedora 18 (3.5.4-1.fc17.x86_64)
- linux /fedora/vmlinuz-3.5.4-1.fc17.x86_64
- initrd /fedora/initrd-3.5.4-1.fc17.x86_64
- options root=UUID=f8f83f73-df71-445c-87f7-31f70263b83b
-
- $ cat /boot/loader/entries/custom-kernel.conf
- title My test Kernel - without initramfs
- options root=PARTUUID=084917b7-8be2-4e86-838d-f771a9902e08
- linux /bzImage
-
- $ cat /boot/loader/entries/redhat-grub.conf
- title GRUB
- efi /EFI/redhat/grub2-efi/grub.efi
-
- $ cat /boot/loader/entries/zzz-efi-shell.conf
- title EFI Shell
- efi /EFI/shell/Shell.efi
-
-Paths are automatically converted from '/' to '\', and a leading '\' is
-added if needed.
-
-Loader options can be stored in:
- (ESP)/loader/loader.conf
-
- $ cat /boot/loader/loader.conf
- timeout 10
- default fedora-*
-
-The timeout is specified in seconds, the default is 0, which suppresses the
-menu. If a timeout is given, in the config file or in the EFI variable
-"LoaderConfigTimeout", the on-screen menu with the default entry selected is
-shown, and a timer counting downwards.
-
-Pressing the '+' or '-' key in the menu will set or clear a custom timeout
-value. The setting is stored persistently in the EFI variable "LoaderConfigTimeout".
-
-The default entry is selected by a pattern match on the configuration file
-names. The matched strings are basenames of the config files translated to
-lowercase and without the ".conf" suffix. The last matching entry in the
-sorted list is selected. If no match pattern is specified, the last entry in
-the list is selected.
-
-This will automatically select the latest Fedora kernel entry:
- default fedora-*
-
-This will automatically select the latest Fedora 18 kernel:
- default fedora-*.fc18.*
-
-Pressing the 'd' key in the menu will mark the selected entry as the default
-boot entry. The entry is identified by a leading '*'. Pressing the 'd' key again
-will clear the setting. The setting is stored persistently in the EFI variable
-"LoaderConfigDefault".
-
-Pressing 'o' allows to edit the options for this bootup.
-
-Pressing 'v' shows the loader and EFI version numbers.
-
-Pressing 'F1' will show the available keys.
-
-The EFI variable LoaderEntryOneShot= can be used to specify a loader entry
-for the next and only the next reboot. The variable will always be cleared
-directly after it is read.
-
-Before executing the selected image, the boot entry indentifier is stored in
-the EFI variable "LoaderEntrySelected" and available during runtime at:
- /sys/firmware/efi/vars/LoaderEntrySelected-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f/
+Further documentation is available in the gummiboot wiki at:
+ http://freedesktop.org/wiki/Software/gummiboot
-The allocated random UUID 4a67b082-0a4c-41cf-b6c7-440b29bb8c4f is meant to be
-shared across tools which implement the config file layout, format, and the EFI
-variables.
+Links:
+ http://www.freedesktop.org/wiki/Specifications/BootLoaderSpec
+ http://www.freedesktop.org/software/systemd/man/kernel-install.html
projects / platform / upstream / gummiboot.git / blobdiff